General Questions and Answers

How many atoms are in 1 mole of Carbon atoms? a) 1.806 x 1024 atoms b) 3 atoms c) 4 atoms d) 6.02 x 1023 atoms

An 85.0 g sample of iron requires 954 J of heat to raise its temperature 25.0°C. What is the specific heat of the iron? a) 3240 J/g°C b) 0.449 J/g°C c) 2.23 J/g °C d) 281 J/g°C

You have a sample of zinc (Zn) and a sample of aluminum (Al). Each sample contains 1.5 x 1023 atoms. Which of the following statements is true about the mass of the samples? The sample of zinc will have less mass than aluminum because zinc atoms have a smaller radius than aluminum atoms. The sample of zinc and aluminum would have the same mass because they have the same number of atoms. The samples of zinc and aluminum do not have mass because these atoms do not have a mass. The sample of zinc will have more mass because the atomic mass of zinc is greater than the atomic mass of aluminum.

How would the energy of the particles of a substance vary between solid, liquid, and gaseous states? Explain your answer.

A material safety data sheet (MSDS) for a chemical is shown below. MSDS H₂PO4(aq) Section 9: Physical and Chemical Properties Physical state and appearance: Viscous liquid Odor: Odorless Color: Clear, colorless Boiling point: 158°C Melting point: 21°C Specific gravity: 1.685 at 25°C Which of these is the IUPAC name for H3PO4(aq)? Phosphorous acid Phosphorous hydroxide Trihydrogen phosphite Phosphoric acid

How many moles of zinc (Zn) are in 392.4 g of Zn? a) 1 mol Zn b) 6 mol Zn c) 65.4 mol Zn d) 25, 663 mol Zn

Use this equation for the following question: 2H₂ + O₂Ⓡ 2H₂O f you have 50 grams of hydrogen (H₂), how many moles of water (H₂O) could be produced? a) 5 mol H₂O b) 50 mol H₂O c) 18 mol H₂O d) 25 mol H₂O

Base A dissociates 25% in water. Base B dissociates 50%. Base C dissociates 75%. Which base is the WEAKEST conductor of electricity? a) Base C b) bases do not conduct electricity c) Base B d) Base A

Take the reaction: PCIs + 4H₂O, H₂PO4 + 5HCI Given: 35.23 grams of H₂O 40.45 grams of PCIs Identify the limiting reactant by formula: Identify the mass of HCI produced: Identify the excess reactant by formula: Identify the mass of excess reactant used:_ Mass of excess that remains unreacted: Molar mass water is 18.00g/mol Molar Mass of HCl = 36.46 g/mol Molar Mass of PCI, = 208.24g/mol Molar Mass of H.PO4 = 98.00g/mol

1. The pressure of a sample of dry air is held constant 2.25 atm while the temperature is decreased from 100. °℃ to 7.0 °C. The original volume of the sample is 43 L. Which of the following is closest to the final volume of the sample? 610 L 32 L 3.0 L 57 L

My theoretical yield of beryllium chloride from a chemical reaction was 10.7 grams. If my actual yield was 4.5 grams, what was my percent yield?

The word equation "Element X reacts with chlorine gas to produce solid Xium chloride" would be represented by which of the following chemical equations? A. X(s) >> Cl(g) + XCI(g) B. X(s) >> Cl₂(g) + XCI(g) C. X(s) + Cl₂ (g) >> XCI(s) D. X(s) + Cl(g) >> XCI(s)

A 20 gram sample of NaOH is used to make a 0.25 L solution. What is the molarity of the NaOH solution? a) 1.0 M b) 2.0 M c) 8.00 M d) 5.00 M

Limiting Reactant Problems: Show the Work needed to get the answer: 1.Take the reaction: 4NH3 + 50₂ →→→ 4NO + 6H₂O Given: 3.25 g NH3 3.50 g of O₂ Identify the limiting reactant: Identify the excess reactant: Molar Mass of NH3 = 17.00g/mol. Molar Mass NO = 30g/mol. Molar Mass of O₂ = 32.00g/mol. Molar mass water is 18.00g/mol

The weatherman reports that today will reach a high of 45°F. Your friend from Sweden asks what the temperature will be in degrees Celsius. What value would you report to your friend? 41. Your parents order an oven from England. The temperature dial on the new oven is calibrated in degrees Celsius. If you need to bake a cake at 350 °F in the new oven, at what temperature should you set the dial? 42. A German automobile's engine temperature gauge reads in Celsius, not Fahrenheit. The engine temperature should not rise above about 225 °F. What is the corresponding Celsius temperature on this car's gauge? 43. Your grandmother in Ireland sends you her favorite cookie recipe. Her instructions say to bake the cookies at 190 °C. To what Fahrenheit temperature would you set the oven to bake the cookies? 44. A gas has a boiling point of -175 °C. At what Fahrenheit temperature would this gas boil? 45. A chemist notices some silvery liquid on the floor in her lab. She wonders if someone accidentally broke a mercury thermometer, but did not thoroughly clean up the mess. She decides to find out if the silver stuff is really mercury. From her tests with the substance, she finds out that the melting point for the liquid is 35°F. A reference book says that the melting point for mercury is -38.87 °C. Is this substance mercury? Explain your answer and show all relevant calculations.

What is the empirical formula of the compound C4H8O4? a) C₂H4O2 b) the compound is already in its empirical formula c) CHO d) CH₂O

In a pressure cooker, a lid is screwed tightly onto a pot so that the air pressure in the pot is increased. What effect, if any, will this have on the boiling point of water in the pot? The boiling point will be raised. The boiling point will be lowered. The boiling point will be unaffected. None of these answers are correct.

Colligative properties depend on which physical property of the solution? a) pressure of particles b) number of particles (the concentration) c) volume of particles d) temperature of particles

Predict the products of the following reaction if Al is higher on the activity series than X. Al(s) + X(NO3)2 → A. No reaction B. AI(NO3)2 + X C. AI(NO3)3 + X D. AIX + NO3

Calculate the change in pH when 6.00 mL of 0.100 M HCl(aq) is added to 100.0 mL of a buffer solution that is 0.100 M in NH3 (aq) and 0.100 M in NH4Cl(aq). Consult the table of ionization constants as needed. ΔpH = Calculate the change in pH when 6.00 mL of 0.100 M NaOH is added to the original buffer solution. ΔpH =

1. Predict: Based on your prior knowledge, predict the following: A. At what temperature will water change from a liquid to a solid (freeze)? B. At what temperature will water change from a solid to a liquid (melt)? C. At what temperature will water change from a liquid to a gas (boil)?

Which of the following descriptions explains the process of water freezing? Water molecules speed up until they escape into a different phase. Water molecules slow down until they begin to bond together. Water molecules are squeezed together by high pressure until they begin to stick to one another. As water molecules cool, their shape changes from rounded to irregular, making them more likely to link to one another.

Click Reset. Set the Water temperature to 0 °C, the Ice volume to 0 cm³, and Add/remove heat energy to -400 J/s. Click Play and wait until all of the water freezes. A. What volume of ice is created from 200 cm³ of water? B. Why do water pipes sometimes burst in the winter?

The fictitious element, Zulfous, is found in the acid, H₂Z. Which name below is the correct name for this acid? A. Zulfuric Acid B. Zulfurous Acid C. Hydrozulfuric acid D. Hydrozulfurous acid

How can the majority of elements on the periodic table be described? A. Good conductors of heat and electricity B. Likely to gain electrons C. Brittle D. Dull

Sodium reacts with a mystery element to form a compound with the formula MgX. If the mystery element bonded with magnesium, what would the most likely formula be for the compound formed? A. Mg₂X B. MgX₂ C. Mg2X₂ D. MgX

After 17.0g of AgNO3 reacts with 19.4g of K₂CrO4, how many grams of AgNO3 are left after the reaction has ended? After 17.0g of AgNO3 reacts with 19.4g of K₂CrO4. how many grams of K₂CrO4 are left after the reaction has ended? Your answer should contain 2 numbers.

When does a diatomic element like Br₂ always have a subscript of two? * Diatomic elements always have a subscripts of two when they are not attached to another element. Diatomic elements always have a subscript of two when they are part of a compound.

QUESTION: If 3 moles of Na3PO4 react with 3 moles of Cu(NO3)2, how many moles of excess reactant will remain after the reaction is complete. 2 Na3PO4 + 3 Cu(NO3)2 → Cu3(PO4)2 + 6 NaNO3 6 moles of excess reactant 1 mole of excess reactant The reaction does not have any excess reactant. 3 moles of exces reactant

Which of the statements below gives the most accurate description of the following reaction? Na₂CO3(s)→ Na₂O(s) + CO2(g) A. Sodium carbonate decomposes with heat. B. Sodium carbonate decomposes to give sodium oxide and carbon dioxide. C. Solid sodium carbonate decomposes to give solid sodium oxide and carbon dioxide gas. D. Sodium carbonate decomposes to sodium oxide and carbon dioxide gas.

QUESTION: If 17.0g of AgNO3 reacts with 19.4g of K₂CrO4, how many grams of Ag₂CrO₂ will be made by the reaction? * 2 AgNO3 + K₂CrO4 → Ag₂CrO4 + 2 KNO3 16.6g of Ag₂CrO₂ 11.2g of Ag₂CrO₂ 36.4g of Ag₂CrO₂ 49.7g of Ag₂ CrO₂ 33.1g of Ag₂ CrO₂

The attached image shows time-lapsed images of a chemical reaction. The equation is shown below. Mg(s) + Cu(NO3)2(aq) → Cu(s) + Mg(NO3)2(aq) According to the chemical equation, what is the identity of the solution seen in the test tube at the beginning of the reaction? A. Cu(NO3)₂(aq) B. Mg(s) C. Mg(NO3)₂(aq) D. Cu(s)

1. A family from Minnesota turns off the heat and flies to Florida for a winter holiday. When they come home, all of their water pipes have burst. What do you think happened? 2. Spaghetti takes about 9 minutes to cook at sea level, but about 14 minutes in the mountains. Why do you think this is so?

If 2.0 mL of 6.0M HCI is used to make a total of 500.0-mL aqueous solution, what is the molarity of the resulting solution? A. 0.024 M B. 1500 M D. 0.83 M

3. Observe: Set up the Gizmo to observe freezing. What do you notice about the temperature while the water is in the process of freezing? 4. Explore: Use the Gizmo to investigate melting and boiling. Does the temperature change while either of these phase changes is occurring?

In the space provided, make a graph of the temperatures. a. Make Celsius your independent variable. It should range from 0-100 along the x-axis. b. Make Fahrenheit your dependent variable. It should range from 0-200 along the y-axis. c. Use a ruler to draw a best fit line. This line does not have to start at zero, but should have an equal amount of data above and below the line.

Sodium sulfate is slowly added to a solution containing 0.0500 M Ca²+ (aq) and 0.0270 M Ag+ (aq). What will be the concentration of Ca2+ (aq) when Ag2SO4 (s) begins to precipitate? Solubility-product constants, Ksp, can be found in the chempendix. [Ca²+] = What percentage of the Ca²+ (aq) can be precipitated from the Ag+ (aq) by selective precipitation? percentage:

Which of the following solutions have a concentration of 5.0M? * OA) 2.0 moles KBr in 0.40 liters of solution B) 119 grams KBr in 0.200 liters of solution C) 1.25 moles KBr in 250 milliliters of solution D) Answers B and C are both correct. E) Answers A, B, and C are all correct.

1. Write the equation for finding degrees Celsius if you know Fahrenheit: 2. Write the equation for finding Fahrenheit if you know degrees Celsius: 3. Write the equation for finding Kelvin if you know degrees Celsius: 4. Write the equation for finding degrees Celsius if you know Kelvin:

Determine the Molarity of a solution formed by dissolving 65.7 g of SrCIO3 in enough water to make a 250.0 mL solution. (Show work for full credit. Just writing the answer, even if correct will not earn full credit.)

One mole of calcium oxide reacts with carbon to form calcium carbide (CaC₂) and carbon monoxide absorbing 110.5 kJ of heat. How much heat is absorbed when 9.00 g calcium oxide reacts with 4.45 g carbon? +13.6 kJ -17.7 kJ -53.2 kJ -13.6 kJ +53.2 kJ +17.7 kJ +40.9 kJ -40.9 kJ

Which statement describes sulfur in its natural state? Clear, odorless gas Yellow, pungent gas Clear crystalline solid Yellow crystalline solid

QUESTION: Water is added to 235.4 grams of K₂Cr₂O7. The solution is mixed and then more water is added to the solution until the solution's final volume is 400 milliliters. The solution is mixed for a second time. What is the molarity of the solution? 0.002 M 0.6 M 6 M 0.005 M 1 M 2 M

If 4 moles of NaOH react with 1 mole of CdCl₂, how many moles of Cd(OH) will be made by the reaction? CdCl₂ + 2 NaOH → Cd (OH)2 + 2 NaCl The reaction will not make zero moles of Cd(OH)₂ 2 moles Cd(OH)2 4 moles of Cd(OH)2 1 mole of Cd(OH)2

Use the diagram below to answer the following question. KNO3 ZrSO2 NH4Cl NaOH CaS Which of the solid substances could be added to the beaker to create a sulfide compound as a precipitate? A. Potassium nitrate B. Zinc sulfate C. Ammonium chloride D. Sodium hydroxide

Why do the following materials not react? Na2SO4 (aq) + Mg(NO3)2 (aq) → No Reaction Because MgSO4 is soluble in water. Because NaNO3 is insoluble in water. Because NaNO3 is soluble in water. Because MgSO4 is insoluble in water. Because NaNO3 and MgSO, are both soluble in water.

Will a reaction happen? Why? * Mg(s) + AgNO3(aq) → No reaction happens because Magnesium is less active than the Silver in the compound. Yes, a reaction happens because Magnesium is less active than the Nitrate in the compound. No reaction happens because Magnesium is more active than the Nitrate in the compound. Yes, a reaction happens because Magnesium is more active than the Nitrate in the compound. No reaction happens because Magnesium is more active than the Silver in the compound. No reaction happens because Magnesium is less active than the Nitrate in the compound. Yes, a reaction happens because Magnesium is less active than the Silver in the compound. Yes, a reaction happens because Magnesium is more active than the Silver in the compound.

H2+N2->NH3 How many moles of nitrogen is required to make 8 moles of ammonia? How many grams of ammonia will be made total? How many moles of Hydrogen gas will you need?

For all of the problems below you will need to do a mole-mass conversion. Each problem will involve two steps. 5. What is the molarity in 650. ml of solution containing 63 grams of NaCl? 6. How many grams of Ca(OH)2 are needed to produce 500. ml of 1.66 M Ca(OH)2 solution?

Given 186.7 g of BaSO4, answer the following. (Show work for full credit. Just writing the answer, even if correct will not earn full credit.) 1. How many moles of barium sulfate is there? 2. How many molecules of barium sulfate is there?